‘Costly’ reason not to use Touch DNA

A major reason behind CBI’s decision not use an advanced DNA profiling technique — the Low Copy Number (LCN) or Touch DNA — to examine evidence in the murders of Aarushi Talwar and Hemraj Banjade was allegedly its prohibitive cost.

The investigating team from Central Bureau of Investigation (CBI) was required to pay £60,000 — around R42 lakh — to a British forensic laboratory to access its expertise in using the LCN technique and examine a few key samples found at the crime scene, from which regular DNA profiling techniques could not extract much, said an agency source.

The “prohibitive cost”, along with experts’ opinion taken by the CBI that the technique — used in the UK, Netherlands and New Zealand — “did not give robust results” made the agency not use it, the source explained.

The CBI had sought opinion from the Scotland Yard on the technique. “Three Scotland Yard experts, along with the Hyderabad-based Centre for DNA Fingerprinting and Diagnostics, said the LCN technique was not reliable. In this background, considering the prohibitive cost of £60,000, a decision was taken against using it,” said the source. The LCN technique, unlike regular DNA methods, can produce result even from a small sample of three-four cells.

The CBI wanted to use the technique to extract the killer(s)’s DNA profile from a handprint and a golf club.